salt

Hi all (I apologize if this is posted in wrong spot....I really stink at choosing where to post) This is my chickens first snow (and my first snow having chickens) I need to salt my steps and pad so my dog wont break a leg or something worse. I bought that driveway salt that says its safe for animals,but I want to be absolutely sure its ok if my chix decide to eat it. Does anyone else use this stuff?
I do have some kosher salt and some sea salt but it is not as effective. Any suggestions would be greatly appreciated t/y..craig